Means for detecting electrical oscillations.



E. E. BUTCHER.

, Ta i Patented. Feb. 26,1918.

3 SHEETS-SHEET I.

E. E. BUTCHER.

MEANS FOR DETECTING ELECTRICAL OSCILLATIONS.

, APPLICAJION FILED MAR. 24, 1914.

a SHEETS-SHEET 2.

Patented Feb. 26,1918.

E. E. BUTCHER.

3 SHEETS$HEET 3- Patented Feb. 26, 1918.

ELMEE, E. BUTCHER, OF INTERLAKEN, NEW JERSEY, ASSIGNOR TO MARCONIWIRELESS TELEGRAPH COMPANY OF AMERICA, A CORPORATION OF NEW JERSEY.

MEANS FOR DETECTING ELECTRICAL OSGILLATIONS.

Specification of Letters Patent.

To all whom it may concern:

Be it known that I, ELMER E. BUTCHER, a citizen of the United States,and a resident of Interlaken, in the county of Monmouth, State of NewJersey, have invented certain new and useful Improvements in Means forDetecting Electrical Oscillations, of which the following is aspecification.

The general object of my invention is to increase the sensitiveness ofthe detecting means for electrical oscillations so as to amplilfy minuteimpulses of weak received signa s.

I attain this object by providing detecting means in which the highestpossible potential obtainable from a given amount of energy derived fromthe received signals is impressed upon a detector which preferably I isa multiple element valve detector, and by so associating the circuitsthat the secondary circuit shall contain an inductance which isrelatively large and is approximately the greatest possible inductancefor a given wave length and a relatively smallcapacity, the coilsconstituting the inductance having a natural period approximately equalto the period of the received oscillations. The secondary circuit ispreferably grounded at one or more points which are substantially themost remote electrically from the terminal of the detector to which thesecondary circuit is connected.

By the use of my invention in connection with a single multiple elementvalve detec tor, I am able to obtain a greater amplification of weakreceived signals than by the use of other means, including the wellknown arrangement of three of such valve detectors in cascade.

I shall describe in this specification and show in the drawingsoperative forms which my invention may take, but the specification anddrawings should not be understood as showing the only forms in which myinvention is useful. It is obvious that many modifications of it may bemade without departing from the spirit of my invention and that it maybe used for various purposes and I, therefore, do not intend to limitmyself either to the specific use to which my detecting means areillustrated as being put, nor to the'exact form shown. For instance, mydevice might be modified so that an inductive instead of a directcoupling, or both,

might be used, or instead of using the three element valve type ofdetector illustrated, other forms of multi-element valve detector mightbe used. Nor do I intend to confine myself to the use of my improveddetecting means as a means'for detecting any particular kind ofelectrical oscillations, as they may be used without modification forthe detection and amplification of both the damped and undampedoscillations.

In the drawings, as in Figure 1, I have shown my invention in connectionwith the receiving end of a wireless telegraph system. In Fig. 2 I haveshown a modification of Fig. 1 whereby a more exact tuning may beobtained. Fig. 3 shows a further modification.

Although it have shown my invention in connection with wirelesstelegraphy, this is not the only use to which it may be put, as it maybe used wherever it is desired to detect electrical oscillations as, forinstance, in wireless, or wire'telephony, or wire telegraphy, in mannerswhich will be evident to those skilled in the art.

Referring to Fig. 1, 1 is the aerial which includes a coil 2 which maybe used both as an aerial tuning inductance and as the primary of anoscillation transformer. The aerial is earthed, as usual at 3. Thesecondary circuit is an open circuit and includes an adjustableinductance 5, which inductance preferably consists of a coil having avery much larger number of turns than inductances heretofore used in thesecondary circuits at the receiving end of wireless telegraph systems;so large a number, in fact, that the coils of the secondarycircuit,.that is, the coil 5 and that portion of the coil 2 which isbelow the point of attachment of the wire leading to the coil 5,together have a natural period equal approximately to that of thereceived oscillations. The remainder of the secondary circuit has littleefiect upon the periodicit of the entire circuit, so that the perioicity of the secondary circuit is practically equal to that of itscoils.

By open circuit I mean a circuit which oscillates as an open circuit orlinear oscillator, after the manner of an'Oudin coil,

Patented Teba 20, TNT...

' surging of the charging current incident to the rise oftheoscillating-voltage of the end terminating in the detector.

Coil 5 is connected to the earth by means of a connection which mayinclude a small variable condenser 1, by being connected to a suitablepoint in coil 2. In addition to the direct connection with the aerial,coil 5 may be inductively coupled therewith to a greater or less degree.Fig. 1 may be taken to illustrate such an arrangement, as well as one inwhich no such inductive relation exists, as is shown in Figs. 2 and 3.It will be understood that if the points of connection of coil 5'withthe aerial circuit be moved down to the point 3, the coupling isentirely inductive, and in such event the inductive coupling isnecessary. Where inductive coupling is employed grounding is not es-'sential but the inductive coupling should be made at a point in the opencircuit remote from the detector. a Condenser 4 may be inserted in thesecondary circuit at various points, or may be dispensed with altogetheras it is not essential to the operation of my device, but improves theeffects produced. The secondary circuit is connected to one of theelements, preferably the grid element 6, or other cold element of amultiple element valve detector. The three-element detector illustratedis not essential to the operation of my device, since a two-elementdetector, such as a Fleming oscillation valve, or variousdothermulti-element detectors may be use The multiple element valve detectoris preferably in the form of a sealed vessel containing a'plate element7, which is connected to a battery 8 and a telephone or other indicatinginstrument 9, which may be shunted by a condenser 10, the other terminalof the indicating instrument being connected to the circuit includingthe filament element 11 of the detector.

The filament element 11 is connected with a battery 12, the batterystrength being so controlled as to properly heat the filament.

In the'operation of my device I first adjust the inductance of theaerial circuit 1, 2, 3 so thatthis circuit is in resonance with theincoming signals. The batteries 8 and 12 and condenser 10 are thenadjusted so that the detector isin a condition of maximum sensitiveness.I then adjust the capacity of the variable condenser 4 and the length ofthe coil 5, until a satisfactory response is obtained in the telephone9.

I In Fig. 2 I have shown a modification of However, I do not recommendthe use of 4 this condenser under all conditions, since capacity in thesecondary circuit is in general to be avoided, but under certainconditions as, for instance, in the reception of very long wave lengths,a small capacity has a certain utility.

In Fig. 3 I have shown a further modification WhlCh consists ingrounding one side of the filament element of the detector on a wire 14.This arrangement is useful in certain cases as, for instance, in thepresence of undesirable electrical disturbances.

What I claim is:

1. Means for detecting electrical oscillations, comprising a circuittuned to the period of the oscillations to be received, and a secondopen circuit associated therewith, containing a multiple element valvedetector, an inductance, the natural period of said inductanceapproximating that of the received oscillations.

2. Means for detecting electrical oscillations, comprising a circuittuned to the period of the oscillations to be received, a second opencircuit associated therewith, containing an inductance, the naturalperiod of said inductance approximatin that of the receivedoscillations, and a mu tiple element valve detector, one element ofwhich is connected to the second circuit.

3. Means for detecting electrical oscillations, comprising a circuittuned to the period .of the oscillations to be received, an open circuitassociated therewith and connected to an element of a multiple elementvalve detector and grounded at a point electrically most remote fromtheconnected detector element.

4;. Means for detecting electrical oscillations, comprising a circuittuned to the period of the oscillations to be received, asecondcircuitassociatedtherewith,containing an inductance, the naturalperiod of said inductance together approximating that of the receivedoscillations, and being connected to one element of a multiple elementvalve detector, and grounded at a point electrically most remote fromthe connected detector element.

5. Means for detecting electrical oscillations, comprising an opensecondary circuit containing a multiple element valve type detector,said circuit associated with an aerial.

6. Means for detecting electrical oscillations, comprising an aerial andan open secondary circuit associated therewith and aae'aera terminatingin one element of a multiple element valve detector.

7. Means for detecting electrical oscillations, comprising an aerial, anopen secondary circuit associated therewith, terminating in an elementof a multiple element valve detector, interposed between two otherelements of said detector.

8. Means for detecting electrical oscillations, comprising an aerial andan open secondary circuit associated therewith, containing an inductanceand a multiple element valve detector.

9. Means for detecting electrical oscillations, comprising an aerial, anopen secondary circuit associated therewith containing an inductance andterminating in one element of a multiple element valve detector.

10. Means for detecting electrical oscillations, comprising an aerialand an open secondary circuit containing an inductance and a multipleelement valve detector associated therewith, the natural period of saidinductance being approximately equal to that of the receivedoscillations.

11. Means for detecting electrical oscillations, comprising an aerial,an open secondary circuit associated therewith and containing aninductance, the natural period of said inductance being approximatelythat of the received oscillations and terminating in an element of amultiple element valve detector,

interposed between two other elements of said detector.

12. Means for detecting electrical oscillations comprising a groundedopen secondary circuit containing a multiple element valve detector,said circuit associated with an aerial.

13. Means for detecting electrical oscillations, comprising an aerial,and a grounded open secondary circuit associatedtherewith andterminating in one element of a multiple element valve detector.

14. Means for detecting electrical oscillations, comprising an aerial, agrounded open secondary circuit associated therewith, terminating in anelement of a multiple element valve detector, interposed between twoother elements of said detector.

15. Means for detecting electrical oscillations, comprising an aerialand a grounded open secondary circuit associated therewith, containingan inductance and a multiple element valve detector.

' 16. Means for detecting electrical oscillations, comprising an aerial,a grounded open secondary circuit associated t erewith, containing aninductance and terminating in one element of a multiple element valvede- 1 tector.

17. Means for detecting electrical oscillations, comprising an aerial,and a grounded open secondary circuit containing an inductance and amultiple element valve detecend and connected at the other end to anelement of a multiple element valve detector.

20. Means for detecting electrical oscillations,,comprising an aerial,an open secondary circuit associated therewith and containing aninductance, the natural period of said inductance being approximatelythat of the received oscillations and connected at one end to the groundand at the other end to an element of a multiple element valve detector.

21. Means for detecting electrical oscillations, comprising an aerial,an open secondary circuit associated therewith, contain ing aninductance and connected at one end to an element of a multiple elementvalve detector, and to the ground at a point electrically most remotefrom the said connected detector element.

22. Means for detecting electrical oscillations, comprising an aerial,anopen secondary circuit associated therewith, containing an inductance,the natural period of said inductance being approximately that of thereceivedoscillations and connected at one end to an element oi amultiple element valve detector, interposed between two other elementsof said detector and at the other end to the ground.

23. Means for detecting electrical oscillations, comprising a secondarycircuit containing a multiple element valve detector, said circuithaving the form of an open oscillating circuit and having a naturalperiod approximating that of the received oscillations.

24. Means for detecting electrical oscillations, comprising a secondarycircuit in the form of anopen oscillating circuit, having a naturalperiod approximately that of the received oscillations connected to anelement of a multiple element valve detector and grounded at a pointelectrically most remote from the said connected detector element.

25. Means for detecting electrical oscillations, comprising an aerial, asecondary circuit having a natural period approximately that of thereceived oscillations connected at one end to an element of a multipleelement valve detector and at the other to the aerial circuit.

26. Means for detectin electrical oscillations comprising a secon arycircuit having a natural period approximately that of the receivedoscillations, a multiple element valve detector to one element of whichthe secondary circuit is connected, the secondary circuit beingconnected to the ground at a point electrically most remote from theconnected detector element.

27 Means for receiving electrical impulses comprising in combination aprimary circuit, and an open secondary circuit associated with saidprimary circuit, said secondary circuit including a high inductance ascompared to the secondary capacity and a detector.

28. Means for receiving electrical impulses comprising in combination aprimary circuit, and a grounded open secondary circuitassociatedtherewith, said secondary circuit containing a high inductance comparedto the secondary capacity and a detector.

29. Means for detecting electrical? impulses comprising a primarycircuit, and a secondary circuit associated therewith including a veryhigh inductance compared to the capacity thereof and a detector.

30. Means for detecting electrical impulses comprising a primarycircuit, a secondary circuit associated therewith including a very highinductance compared to its capacity, a vacuum valve detector connected7. to said secondary circuit, and an indicating ELMER E. BUTCHER.

Witnesses:

WM. M. EARL, WALTER S. JoNEs.

